Various constructions are known for forceps, hemostats, and like manually operable clamps which have a generally scissors-like working action. Clamps of this description are widely used for many different purposes in the health care industry and also find wide application in areas apart from medically-related uses. Frequently, such clamps include selectively operable locking means for maintaining the clamping force created by the clamp, such as for clamping of a rubber tube to maintain the tube in a closed or constricted condition.
While in the past many of the above-described clamps have been fabricated from suitably corrosion-resistant metallic materials, clamps of such construction are relatively expensive. Because of the highly versatile nature of such clamps, efforts have been more recently made to perfect a relatively inexpensive clamp made of plastic materials. By providing a selectively lockable clamp which is relatively inexpensive, such a clamp becomes practical for use in not only many health care-related applications, but also for use such as in manufacturing operations, hobby activities, or whereever else a selectively and easily applicable clamping force can be advantageously employed.
One previous plastic clamp which has been developed is of unitary plastic construction, including a pair of pivotally interconnected pincer portions, and a pair of pivotally interconnected handle portions. One end of each pincer portion is pivotally connected to one end of a respective one of the handle portions, with all of the pivotal connections of the clamp provided by integral "living" hinges. This previous clamp further includes a pair of cooperating locking teeth respectively provided on the handle portions of the clamp. The locking teeth are engagable generally be movement of the handle portions toward each other, which in turn causes the respective ends of the pincer portions to move together for clamping. Disengagement of the locking teeth for release of the clamp is effected by relative disengaging movement of the handle portions transversely of a plane which extends through the pincer and handle portions of the clamp.
One serious problem encountered with the use of the above-described plastic clamp is the relative ease with which the locking teeth of the clamp can be disengaged. Primarily due to the inherent flexibility of the plastic material from which such a clamp is fabricated, relatively little force is required to relatively move the handle portions of the clamp for disengaging its locking teeth. Consequently, a relatively slight disturbance of the clamp can result in its inadvertent release. At best, such inadvertent release of the clamp is inconvenient, while at worst (particularly in medically-related applications) inadvertent release of the clamp can be potentially serious.
Accordingly, a very real need exists for an easily-operable, relatively inexpensive one-piece plastic clamp which can be selectively maintained in a closed or clamping condition, and which is configured to resist inadvertent or accidental release.